Rotary dies



Dec. 5, 1967 A. J. SARKA 3,355,969

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` IMIENTOR.L

ALBERT J. SARKA ATTORN EYS Dec.. 5, 1967 A. J. SARKA 3,355,969

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BYALBERT J. SARKA Mm: @Wl/'ZJ d ATTORNEYS United States Patent O M 3,355,969 ROTARY DIES Albert J. Sarlra, Cleveland Heights, Ohio, assigner t Harris-Intertype Corporation, Cleveland, Ohio, a corporation of Delaware Filed Sept. 25, 1964, Ser. No. 399,196 12 Claims. (Cl. 76--107) The present invention relates to rotary dies and to methods of preparing and setting up such dies.

'Cooperating rotary dies are used to perform various sheet-forming operations, such as cutting, creasing and ernbossing. The cooperating rotary dies of the type to which the present invention relates are curved cylindrically and have forming elements thereon which cooperate with each other to form the sheet material passing therebetween. These cooperating elements must register with each other at the forming line as the dies are rotated. If the forming elements do not register properly, the material will not be properly formed.

Rotary dies may be made by removing material, such as by etching, from flat bendable plates to form cooperating die elements on the working side of the plates. When such dies are used, certain areas of the dies must rbe present for functional reasons and there are other areas which may be termed nonfunctional areas which do not perform functions and the presence or absence of the original plate in these areas does not interfere with the ability of the die to perform its functions.

One of the problems in making die plates for rotary machines while the plates are flat is that the plates tend to grow when bent around a cylinder. I have found that the growth characteristics of the plates will often cause the cooperating die elements to misregister but that this can be overcome by balancing the cross-sectional areas of die plates so that the growth characteristics of the dies on bending are substantially the same. In accordance with the broader aspects of the present invention, the nonfunctional areas of the dies are selectively removed, i.e. recessed, to provide dies with balanced cross-sectional areas.

In the preferred form, the die which would have the larger cross-sectional area if the Working side of the dies were recessed in all Iareas except where the material is required for functional reasons is formed by so recessing the plate to provide a fully recessed die plate except for functional lands rising from the working side of the die. Then, to balance the cross-sectional areas of the dies the other die is not recessed in certain areas which would be removed to thereby provide a pair of dies, one of which has the original plate recessed except in the areas of the functional lands and the other of which has only portions of the original plate in the nonfunctional areas recessed so that the dies are balanced in cross-sectional areas t0 make the growth characteristics the same.

It is therefore an object of the present invention to provide a new and improved rotary die, and method of forming the same, where the die is in the form of a flexible plate and has sheet-forming elements thereon for registering with sheet-forming elements on a cooperating flexible die, the cross-sectional thickness of the cooperating dies being controlled so that the sheet-forming dies will register properly when the dies are bent around cooperating cylinders of a rotary sheet-forming machine.

Further objects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiment thereof made with reference to the accompanying drawings and forming a part of the present specification for all matter disclosed therein and in which:

Patented Dec. 5, 1967 FIG. 1 is a fragmentary sectional view showing cooperating cylinders of a rotary sheet-forming machine;

FIG. 2 is a sectional perspective view of dies for forming sheet material and illustrating the principle of rupturecutting;

FIG. 3 is a perspective sectional view of the dies of FIG. 2 but with the structure of the dies modified;

FIG. 4 is a perspective sectional view of the dies of FIG. 2 with the dies modified to perform both la cutting and a creasing operation;

FIG. 5 is a perspective sectional view of the dies of FIG. 4 with certain modications;

FIG. 6 is a perspective view of a cut away portion of a die;

FIG. 7 is a view showing the die of FIG. 6 with a cooperating die;

FIG. 8 is a plan view of one of the dies shown in FIG. 1;

FIG. 9 is a cross-sectional view of the die shown in FIG. 8 and is taken substantially along line 99g FIG. 10 is a plan view of another of the dies shown in FIG. l; and

FIG. ll is a cross-sectional View of the die shown in FIG. l() and is taken substantially along line 11--11.

The present invention will be described with reference to dies for performing the operations of cutting and creasing sheet material to form a cardboard container blank, such as is used to form a frozen food container. It will be understood, however, that the invention is also applicable to dies for performing these operations separately as well as to dies for Iperforming similarsheet-forming operations.

The sheet-forming operations are to be done by a rotary machine having cooperating rotary cylinders 10, 11. The cylinders 10, 11 are shown in FIG. 1 and the cylinders 10, 11 have cooperating dies 12, 13 thereon which snugly lit the surfaces of the cylinders and which cooperate at a material-forming line to form sheet material passing between the cylinders. The sheet material may be in the form of a continuous web or in the form of individual sheets which are handled in succession. The dies, in the preferred embodiment, are etched flexible plates which are bent around the cylinders and which are fastened to the cylinders at their opposite ends. The cylinders have gaps 10a, 11a, therein in which means is provided for fastening the die plates to the cylinder. The means for fastening the die plates on the cylinders does not yform a `part of this invention and the plates in FIG. 1 are simply shown as having their ends connected to the cylinder by bolts 14 which pass through the plates and thread into the adjacent side wall of the cylinder gap.

The cylinder 1() is a sheet-carrying cylinder and has sheet grippers 15 in the gap 10a which grip the leading edge of a sheet to be operated on and carry it through the forming line between the cylinders 10, 11. As the cylinder is rotated, conventional feed or transfer cylinders may be used to feed the sheets to the cylinder 10 and a conventional delivery cylinder may be used to receive and deliver the formed sheet from the cylinder 10.

In the illustrated form of the present invention, the plates 12, 13 are tlexible plates which have cooperating sheet-forming elements thereon for cutting and creasing a sheet. The cutting of the sheet along any given line is effected in the illustrated dies by a rupturing technique in which the material along the: line is compressed between the sheet-forming elements.

In rupture-cutting, the sheet material is compressed by the dies along the line of severance and one die is stepped inwardly on one side of the line by at least the thickness of the sheet material to provide clearance for the sheet material on that side of the line, and the other die is stepped inwardly on the other side ofthe line of severance to receive the sheet material on that side of the line. FIG. 2 illustrates the principle of rupture-cutting with Hat dies 20, 21 for cutting along a single line extending transversely of the die, i.e. across its direction of movement when on the cylinder, The die 2t) has an outer step portion 20a on one side of the line of severance and a step portion 2Gb on the opposite side of the line which is stepped inwardly from the outer step portion by at least the thickness of the sheet material. The die 21 has an outer step portion 21a opposite the inner step portion 2Gb and which overlaps the outer step portion 20a along the line of severance so as to compress the material in the area of the overlap. The overlap in rupture-cutting is preferably a maximum of .O05 inch. The outer step portions of the dies are normally separated at the forming line by a -gap of .002 to .004 inch.

The die 21 also has an inner step portion 2lb opposite to the outer step portion 2da of the die 20 and the step 2lb is of a depth at least the thickness of the sheet material. When the material is -compressed by the dies along the line of severance, the material on one side of the line of severance is received in the inner step of one die and the material on the other side of the line is received in the inner step of the other die.

The portions of the outer steps of the dies Ztl, 21 which do not overlap actually perform no function and these outer steps can be cut away as indicated in dot-dash lines in FIG. 2 so that the severing elements of the dies are actually lands c, 21C (see FIG. 3) which project `from the base of the die plate and have a height at least equal to the thickness of the material. Moreover, if a portion of the outer step 21a of die 21 is removed, the inner step portion 2Gb of the die 2t) can be provided, if desired, with a land 23 opposite to the cutaway outer step, as is shown in FIG. 3. This land would perform no function in forming the material.

In forming sheet material to make blanks, such as carton blanks, it is desirable to slit the blank along lines which extend perpendicularly to the line of severance extending lengthwise of the dies. In such as case, the male die would be provided with lands or outer steps which rise from the inner step portion 20h and which extend generally perpendicularly to the shoulder between the inner step portion 2Gb and the outer step portion 20a. Such a die is shown in perspective in FIG. 6 and in section in FIG. 7 with a cooperating die. The dies in FIGS. 6 and 7 and the parts thereof have been given the same reference numerals as the dies in FIG. 2 since the dies are basically the same except for the addition of the lands which have been designated by the reference numerals 2da, 2411. As is shown in FIG. 7, the outer step portion 21a of the die 21 must be inset along the lands 24a, 24b. The insets are shown above the lands 24a, 214i: and are designated by the reference numerals 25, 26, respectively. The insets 25, 26 in the outer step portion 21a of the die 21 are necessary so that the outer step portion 21a will have a portion 27 which overlaps the land 24a and a portion 28 which overlaps the land 24]), with the die being inset to provide a shoulder that terminates the overlapping portion and as Well as a space for receiving the sheet material in the die 21 on one side of the line of severance. In FIG. 7, the insets in the die 21 are shown as disposed to the right of the lands 24a, 2411, respectively. It will be understood that the insets could be disposed to either side of the lands 24a, 2419. Here again, however, the outer step portion of the die 21 could be additionally cut away along the dot-dash lines shown in FIG. 7 without affecting the function of the die 21. It will be appreciated however, that the cutaway portions indicated by the dot-dash lines Would not extend into the functional part of the die necessary to provide the land 21C.

The dies may be made to perform both cutting and creasing operations. FIG. 4 shows two flat dies 30, 31 for performing such an operation on sheet material. The dies 30, 31 are similar to the dies 20, 21. The die 30 has outer and inner steps 30a, 30b, respectively opposed to inner steps 31b, 31a of the die 31 with the outer steps overlapping along the line of severance to effect a rupture cut. The inner step 3111, however, has a land 33 projecting outwardly therefrom along the line of creasing and which is adapted to register with a recess or groove 3d in the outer step 31a to force the material into the groove. The land 33 only projects outwardly to the height of the outer step portion 30a of the die 30 and the groove 34 has a depth at least equal to the thickness of the sheet material so that the sheet material may bend around the land 33; preferably the clearance between each side of the groove 34 and the land 33 is the thickness of the sheet material. It will be noted that the groove 34 is formed in the die having the outer step portion at the line of creasing and the projecting land is formed on the die having the inner step portion at the line of creasing. Even when a creasing operation is to be performed, the outer step of die 31 can be cut away as indicated in dotdash lines in FIG. -4 and as was explained in connection with FIG. 2, as long as lands 35, 36, shown in FIG. 5, are left to define the opposite sides of the groove 34 and force the sheet material about the land 33 as the dies come together. The lands 35, 36, then, define the groove 34, i.e., the female forming element for creasing, and the land 33 provides the male forming element.

Consequently, it can be seen that the dies may be formed so that lands rise along the line of severance to cooperate with lands on the cooperating die which are offset therefrom and in the case of creasing, the male sheet-forming element may rise as the land from the base section of the dies and the female sheetforming element may comprise spaced parallel lands for defining a groove which is adapted to register with the male land. Moreover, it will be appreciated that there are certain areas of the dies, which may be termed nonfunctional areas, and they may be selectively removed or left intact Without affecting the function of the die for cutting or creasing.

The flat dies 30, 31 as illustrated in FIG. 4 could not be wrapped around a `cylinder and have the elements in registry with each other because of the fact that the outer surface of each die will grow differently when bent around a cylinder. When the dies are wrapped around their respective cylinders, the iinal positions of the sheet-forming elements on the outer surfaces and relative to each other will depend upon this growth. For this reason, such cooperating dies have not, heretofore, been formed flat and then bent or curved into position. In the case of dies 30, 31 as shown in FIG. 4, experience has shown that the elements would not register with each other if the dies were bent around cooperating cylinders of a sheet-forming machine. Since the growth of the outer surface of the dies and the shifting of the sheet-forming elements occur in a direction around the periphery of the cylinder, this problem of misalignment would not be too critical in the case of cutting or creasing along lines which extend perpendicular to the trailing and leading edges of the die, except that the cut or crease might not be made for the full length of the line, but becomes a major problem when the lines extend in a direction generally across rather than around the cylinder. Any shifting of the cooperating elements relative to each other when the lines of cutting or creasing extend across the cylinder might cause the severing elements to fail to cut, and creasing elements may cause cutting instead of creasing. However, in accordance with the present invention, the dies are formed in such a manner that the sheet-forming elements Will not Shift out of registry with each other as they are bent around cylinders of the same diameter. To accomplish this, nonfunctional portions of the die, such as sections of the outer step portions 30a, 31a, are removed in order to balance the cross-sectional areas of the dies. When the dies have substantially the same cross-sectional area in the direction of bending, any shifting of the elements will be substantially the same and the sheet-forming elements will maintain registry. Consequently, if the dies are formed of flexible material, they can be bent from a fiat position, which may be the position in which the die plates are when provided with their forming elements, to curved positions around cylinders of the same diameter without the danger of losing registry of the sheet-forming elements. The removal of the die material can be done by etching or by any other suitable process, such as machine or chemical milling. When the dies are formed in accordance with the preferred embodiment of the present invention, they will have uniform bases of substantially the same thickness and lands for severing and creasing will rise from the bases and the cross-sectional areas of the dies will be maintained substantially equal so as to maintain the sheet-forming elements in registry as the dies are bent around their respective cylinders.

The dies 12, 13 are illustrated in FIGS. 8 and 10. The carton blank formed by the dies 12, 13 is the type of blank used to make food containers. The male die 12 includes a continuous closed land 41 defining the outline of the carton blank, which is generally rectangular in configuration, and the severing lands along the respective sides have been given the reference characters 41a, 41b, 41e` and 41d. The land 41a defines the front edge of the carton blank and lies along the leading edge of the die, while the land 41c lies along the trailing edge of the die. The area of the die outside of the land 41 would normally be the outer step of the die and this has been etched away, as is apparent from FIG. 9, to balance the cross-sectional area of this die with the die 13. The die 12 also has a plurality of creasing lands rising therefrom, which outline the top, bottom and back areas of the carton. The top, back side and bottom areas are disposed in side-by-side relationship inside the area outlined by the closed land 41 and, as viewed in FIG. 8. The top of the carton is outlined by male creasing lands 45, 46extending parallel to the trailing and leading edges of the die and by male creasing lands 47, 48 extending between the creasing lands 45, 46 atthe opposite ends thereof. The land 45 is adjacent but inwardly of land 41a. The back side of the carton is outlined by creasing lands including the land 46 and a male land 50 extending parallel thereto on the side thereof remote from the land 45 and by male lands 51, 52 extending between the lands 46, 50 at the opposite ends thereof. The bottom of the carton is outlined by the creasing land 50 and a male creasing land 54 extending parallel to the '55, 56 extending between the lands 50, 54 at the opposite ends of the land. The. area of the die between the creasing land 54 and the adjacent severing land 41c defines the front side of the carton and male creasing lands 60, 61 extend from the opposite ends of the creasing land 54 to `the adjacent severing land 41C. The end sides of the carton are defined by the areas outwardly of the creasing lands 47, 51, 55 along one side of the die, and outwardly of the creasing` lands 48,` 52, 56 along the other side of the die. Sever-ing lands 62, 63, 64, form extensions at both ends of the creasing lands 46, 50, 54, respectively, in the area corresponding to the end side of the carton so that the carton blank will be slit along these lines to enable the end sides to be folded downwardly and upwardly from the top andbottom of the carton and inwardly from the back side of the carton.

The cooperating female die 13 is shown in FIG. l0 and the vdie has severing lands which correspond to the severing lands of the male die but which are offset therefrom in the manner explained with reference to dies 20, 21 and 30, 31 and female creasing lands which cooperate with the creasing lands of the male die to crease the sheet. The creasing lands of the female die and the severing lines have been given the same reference characters as the corresponding lands of the male die with a prime affixed thereto. The outer step portion of the female die would normally be the portion inwardly of the outer edge of a severing land 41 outlining the carton; however, since the die is .formed with severing lands 62', 63', 64', certain areas inwardly of the outline defining land 41 must be cut away for functional reasons to effect the cutting at the lands 62', 63', 64', as explained in connection with the dies shown in FIGS. 6 and 7.

As will be apparent from considering FIGS. 8 and l0, all areas of the dies have been etched away except-for those areas which are functional sheet-forming elements. When the lines of creasing are such that the female die is thrown out of balance so that its growth characteristics are different from that of the cooperating male die when bent or curved around a cylinder, it can be understood that certain of the nonfunctional areas of the male die need not be removed. Lands outside of the outline might be left to balance the growth characteristics of the dies since these are also nonfunctional areas of the male die, or the severing land might be increased in width, as indicated by dot-dash lines on FIG. 8, to compensate for the extra material in the female die because of the double lands defining the female sections of the die. Similarly, lands could beadded to the male die in areas where the female die has been etched out. For example, the lands 70 might be added as indicated in dot-dash lines. While the lands would normally be in the functional area of the male die, the opposing area of the female die, which is a nonfunctional area, has been etched out and the sheet will merely bend around the lands into the space provided by the female die. Consequently, the sheet will not be formed in these areas. Preferably, however, 'the balancing lands are left in areas which are purely nonfunctional areas of the die. When the areas of the female die, opposite to an area of the male die which is normally a functional area in that it receives the sheet, are etched away, the area of the male die becomes nonfunctional. It will be noted, however, that the lands in these nonfunctional areas, due to etching away of the 4female die, terminate short of the creasing lands 45, 46, etc., so that a severing action will not take place between these lands and the creasing lands. Moreover, the growth might be balanced by etching the female die deeper than the male die. When the female die is etched deeper than necessary for functional reasons, the extra depth constitutes the removal of a nonfunctional area.

The method of removing the material from the die may be accomplished, as stated before, by a conventional technique used in preparing relief printing plates. In this technique, the plate, which is preferably approximately twice the thickness of the sheet material to be formed is coated with an etch-resistant, light-sensitive material capable of being hardened upon exposure to intense light. A film having lines of transparency thereon which correspond to the lands to be formed on the plate is placed over the plate having the coating thereon and the light is passed through the transparent lines. The light-sensitive material is hardened in the areas exposed to the light and adheres to the die face of the plate. The unhardened portions of the light-sensitive material which have not been exposed to the light are then washed off, or otherwise removed, and an etching material is applied to the die face of the plate. Since the hardened areas of the light-sensitive material are etch-resistant, only the areas which are not covered by the hardened sensitive material are etched away. Preferably, the etching provides a die plate having a base of substantially uniform thickness from which lands deiining the sheet-forming elements rise. In the preferred method, the plate is approximately twice the thickness of the sheet material to be formed and the etching of the die face to a depth substantially the thickness of the sheet material will result in a plate where the base section is approximately equal in thickness to the height of the lands. It has been found that such a plate when made of d steel will bend satisfactorily even in those cases where the sheet material being handled is cardboard, such as used in forming frozen food cartons and lwhich has a sheet thickness of approximately .016.

It can now be seen that the present invention provides a new and improved method of making and providing rotary dies for the cylinders of a rotary sheet-forming machine. The method enables the dies to be Iformed in the fiat and then bent around the cylinders and fastened thereto. The sheet-forming elements of the dies will maintain registry during the bending operation provided the plates are bent around cylinders of substantially the same size. While the cylinders are preferably the same size, if the cylinders are to be of different sizes, the cross-Sectional areas of the dies may be related in such a manner so as to provide the proper growth characteristics of the dies when bent around the cylinders on which they are to be used so that the sheet-forming elements of the dies will maintain proper registry.

While a preferred embodiment of the present invention has been described in considerable detail, it is hereby my intention to cover all modifications, constructions, and arrangements which fall within the ability of those skilled in the art and within the scope and spirit of the appended claims.

Having described my invention, I claim:

1. The method of forming cooperating dies for rotary cylinders which comprises removing material from first sides of ilexible flat plates at least to the extent necessary to enable the dies to perform their function, balancing the cross-sectional areas of said plates to provide die plates having similar growth characteristics when bent in a corresponding manner by removing a portion only of the material in the other areas of the dies where the material may be removed or left selectively.

2. The method of providing cooperating rotary cylinders of a sheet-forming machine with sheet-forming elements in the form of dies comprising the steps of removing material from one side of flexible flat plates of die material to remove the portions thereof which must be removed to provide the sheet-forming elements of the dies including the step of removing additional material from said side of at least one of said plates to remove a limited part of the nonfunctional portions of the die plate to substantially balance the cross sectional areas of the die plates so that the resultant die plates have base sections of substantially uniform thickness and sheet-forming portions rising to a uniform height from said base sections whereby the plates have substantially the same growth characteristics when bent in a corresponding manner.

3. The method of providing material forming dies for rotary cylinders, said dies having lands rising from the Vsides of plates which are flexible so as to be bendable about the cylinders of a sheet-forming machine, which method comprises removing material from first sides of flexible flat plates at least to the extent necessary to provide the functional sheet-forming areas of the die and recessing the material in the nonfunctional area of the die which has the larger cross-sectional area for the functional portions of the finished die when all material is recessed from said first side except in those areas necessary to provide functional lands and removing portions of the other die only to the extent necessary to form the functional elements of the die and to balance the cross-sectional areas of the dies to give substantially the same growth characteristics when bent in a corresponding manner.

4. The method of forming cooperating die plates adapted to be mounted on rotary cylinders of a machine for operating on sheet material, comprising removing material from rst sides of flexible fiat plates of die material to a depth corresponding to the thickness of the sheet material to remove the portions thereof which must be removed to provide the sheet-forming elements of the dies including removing additional material from said side of at least one of said plates to remove only a part of the nonfunctional portions of the die plate to substantially balance the cross-sectional areas and growth characteristics of the die plates and so that the resultant die plates have base sections of substantially uniform thickness and sheet-forming elements rising to a uniform height from said base section.

5. The method of making male and female rotary dies which comprises recessing all the material on one side of a flexible flat plate except in areas where lands are to be provided to define sheet-forming elements including spaced lands providing female sheet forming elements, and recessing all material on one side of another flexible plate except in those areas where lands are to be provided as sheet-forming elements and in selected nonfunctional areas to provide lands extending parallel to said female lands to balance the growth characteristics of said dies on bending.

6. A male die for use on a rotary cylinder of a sheetforming machine and adapted to cooperate with a female die, said male die comprising a plate of tlexible die material having a base section of substantially uniform thickness and narrow lands rising from said base sections and providing the sheet-forming elements of the die and additional lands rising from said base section in nonfunctional areas of the die to balance the cross-sectional area of the die with that of the corresponding female die, said lands having a height at least equal to that of the thickness of the sheet material to be operated upon.

7. A pair of cooperating rotary dies comprising a female die having a groove therein and a male die having a land to cause material being operated upon to be received in said groove and a recessed portion on opposite sides of said land to receive sheet material being formed, a part of said female die on one side of said groove being recessed to receive sheet material and to Provide a land between the recessed part and the groove and said male die having a nonfunctional land in said recessed portion parallel to said groove for balancing the growth of the dies when bent in a corresponding manner.

8. In the method of manufacturing a bendable die from flexible plates in which one side of a plate is selectively recessed to provide functional sheet-forming lands and functional recessed areas having a predetermined minimum depth and in which nonfunctional areas of the die may from an operational standpoint be recessed or not selectively, the die having a certain average cross-sectional area and growth characteristic if recessed in all nonfunctional areas to said predetermined depth, the method of reducing the growth characteristic of the die on bending to balance the die being formed with a cooperating die to maintain proper registry therewith when the die is bent around a cylinder comprising the steps of recessing the plate while generally fiat to form the functional areas of the die and selectively limiting the recessing of the plate in the nonfunctional areas to provide a die with an increased average cross-sectional area as compared with said certain average cross-sectional area to limit the growth of the die on bending to that required to maintain registry of the die with its cooperating die.

9. The method as defined in claim 8 wherein the recessing in the nonfunctional areas is such that nonfunctional land areas are formed which extend parallel to functional land areas of the die.

10. A flexible die having functional areas on one side 'thereof for forming sheet material defined by recesses providing functional land areas and functional recessed areas and having nonfunctional areas on said side which are recessed in part only to provide nonfunctional growth vbalancing land areas to match the die on bending with 'a cooperating die.

11. A flexible die plate as defined in claim 10 wherein the recessed areas are recessed to a uniform depth.

12. A pair of rotary flexible dies for use on cooperating rotary cylinders to crease llexible sheet material, one of said dies having a male element thereon and the other of said dies having a female element thereon, the elements of said dies being adapted to register when said dies are at and said dies having substantially the same average cross sectional areas to provide substantially the same growth characteristic when bending about the rotary cylinders.

1 O References Cited UNITED STATES PATENTS GRANVILLEY. CUSTER, JR., Primary Examiner. 

1. THE METHOD OF FORMING COOPERATING DIES FOR ROTARY CYLINDERS WHICH COMPRISES REMOVING MATERIAL FROM FIRST SIDES OF FLEXIBLE FLAT PLATES AT LEAST TO THE EXTENT NECESSARY TO ENABLE THE DIES TO PERFORM THEIR FUNCTION, BALANCING THE CROSS-SECTIONAL AREAS OF SAID PLATES TO PROVIDE DIE PLATES HAVING SIMILAR GROWTH CHARACTERISTICS WHEN BENT IN A CORRESPONDING MANNER BY REMOVING A PORTION ONLY OF THE MATERIAL IN THE OTHER AREAS OF THE DIES WHERE THE MATERIAL MAY BE REMOVED OF LEFT SELECTIVELY. 